Social networking sites are a way of getting in touch with old friends and keeping in touch with current ones. Facebook is one of the best-known social networking sites, and is very easy to use. Facebook allows each user to set up a "profile" of themselves, listing details of their education and career, as well as allowing them to upload photos and video clips to share. Each person's profile can be viewed by people listed as "friends". Facebook friends can also post comments on each other's "wall" - a kind of instant email service.
Facebook also allows users to notify their friends of forthcoming events, and groups of common interest can be set up. There are groups covering everything from the state of the chicken nugget to the vagaries of Adam Smith's moral philosophy.
